1. Field of the Invention
This invention relates to a device capable of suction-adhering to a wall surface by the pressure of an ambient fluid such as air or water and treating the wall surface. More specifically, it relates, although not exclusively, to a device capable of suction-adhering to a wall surface of a ship or a building and cleaning or otherwise treating the wall surface.
2. Description of the Prior Art
A device for performing work such as cleaning of an outside wall surface of a ship, an outside wall surface of an oil reservoir tank, an outside surface of a tall building, etc. is proposed in U.S. Pat. No. 4,095,378 to F. Urakami which comprises a pressure receiver housing, a plurality of wheels provided in the pressure receiver housing for contact with the wall surface, a partition having one end connected to the pressure receiver housing and adapted to define a substantially fluid-tight pressure reduction zone in cooperation with the pressure receiver housing and the wall surface upon partial contact with the wall surface, means for discharging fluid from the pressure reduction zone to create a vacuum within the pressure reduction zone, and working means provided in the pressure receiver housing.
In this conventional device, a vacuum is formed within the pressure reduction zone by vacuum-producing means, and a part of the partition is contacted fluid-tight with the wall surface by the fluid pressure acting on the partition owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone. In the meanwhile, the fluid pressure acting on the pressure receiver housing owing to a difference in pressure reduction zone is transmitted to the wall surface via the wheels. As a result, the device is caused to adhere by suction to the wall surface. The device suction-adhering to the wall surface is adapted to move along the wall surface by driving the wheels. Hence, the above-described device can adhere to the wall surface by suction and can move along it. By the working means provided in it, it can perform the desired work such as cleaning of the wall surface.
In the known device, means for causing the device to adhere by suction to the wall surface and move along it and treating means for performing treatments such as cleaning of the wall surface are constructed independently from each other. This structure increases the size and weight of the entire device and leads to a high cost of production.